Four kinds of Fe-2Ni metal injection moulding (MIM) feedstocks with the same powder loading and with similar binder composition except for minor components were prepared and their viscosities at different temperatures and shear rates determined using a capillary rheometer. The flowabilitv and the sensitivity of viscosity to shear rate and temperature were investigated. The viscosities of the binders and the general theological indices of feedstocks were compared. The results show that the minor com- ponents of the binders play a very important role in the rheology of feedstocks. A feedstock based on a PW PP binder can not be used for injection mould-ing owing to severe powder binder separation. A feed-stock based on a PW EVA binder has the lowest viscosity and is the easiest to flow into the mould. The viscosity of a feedstock based on a PW EVA HDPE binder is higher than that of a feedstock based on the PW EVA binder and is lower than that of a feedstock based on a PW HDPE binder. The general rheolog-ical index, which includes the effect of flowabilitv and the sensitivity of viscosity to shear rate and temper-ature, can be used to evaluate the general theological properties of MIM feedstocks. At a reference temper-ature of 150℃ and reference shear rate of 1181 s-1. the general rheological indices for the feedstocks based on the PW-EVA. PW-HDPE, and PW-EVA-HDPE binders are 7-8. 4-0. and 93 respectively. The feedstock based on the PW EVA HDPE binder has the best general rheological properties and is most suitable for injection moulding. The mechanical prop-erties and shrinkage homogeneity of MIM tensile bars prepared with the feedstock based on the PW EVA HDPE binder are also the most acceptable.

从材料的综合流动曲线及聚合物、粘结剂的流动性能，分析了金属注射成形喂料的流动行为，给出了用毛细管粘度计测量金属注射成形喂料粘度并确定其流动曲线参数的分析方法。

The application of PIM (powder injection molding) process of cemented carbide parts bas been studied. Two kinds of cemented carbide powders, with the particle size of 3um and 0.4um respectively, were used in the experiments. Two kinds of binders were applied. The rheological properties of feedstocks were studied. The thermogravimetry analysis and thermal debinding cycles were investigated. Possible defects introduced in PIM process steps were described. The influences of holding temperature and holding time during debinding on the carbon content in compacts were studied. The mechanical properties of cemented carbide parts prepared with different partiele sized powders were compared.

采用分步快速脱脂曲线，PW-EVA-HDPE粘结剂有序地分为三步脱除，首先是熔点最低的Pw在350℃脱除，然后升温至420℃脱除EVA，最后在500℃脱除HDPE。PW-EVA-HDPE多组元粘结剂热脱脂主要分为初期孔隙通道形成期、孔隙通道形成后剩余PW脱除期及后期剩余EVA和HDPE脱除期。其中孔隙通道形成期和连通孔隙通道形成后剩余PW脱除期的动力学控制因素为液相扩散，即Pw的热分解气体Vpw在聚合物熔体中的扩散。

The 1724PH stainless steel compacts sintered at 1 380 ℃for 90 min have the best me2 chanical properties and the good microstructure with homogeneously distributed pore structure and the moderate2sized grains. Whereas the compacts sintered for 60 min and 120 min show an inadequate and an over2sintered microstructure re2 spectively. The compacts sintered at 1380 ℃for 90 min have the density of 7.70g/cm3, the strength of 1275MPa, the elongation of 5%, and hardness of HRC36. With the increase of sintering temperature, the density, strength and hard2 ness increase, while the elongation decreases. The 1724PH stainless steel has good corrosion resistance, showing an activa2 tion2passivation polarization curve. But the passivation potential range is narrow and the spot corrosion potential is low, in2 dicating a low anti2spot corrosive properties.